I wouldn't mind seeing Fun. They are current and it would work perfectly having Nate Ruess around to sing JMGAR
If not him....I dunno. Adam Lambert would be fun! Ithink he could get a crowd going. Not sure if he's to big at this point. Or....The Lumineers would be interesting

Deffo Butch Walker. He said at his show in Manchester last month how difficult he finds it to come over to Europe, so it'd give his European fans chance to see him again and he could do a few of his own shows as well like last time.